An improved delay-hopped transmitted-reference ultra wideband architecture

The delay-hopped transmitted-reference (DHTR) ultra wideband (UWB) architecture was proposed by Hoctor and Tomlinson as a candidate for impulse UWB systems working in multipath fading channels. Compared to the RAKE transceiver, the DHTR transceiver does not require channel estimation, and the correlation can be performed in the analog domain. Since the analog-to-digital converters (ADCs) are now placed after the correlators, high sampling-rate, high-power ADCs are no longer required. As a result, the DHTR architecture is suitable for low-power, low-data-rate impulse UWB applications, such as RF tagging and sensoring. However, the proposed DHTR architecture will produce discrete spectral spikes in the transmitted signal, which are undesirable because the emissions of the UWB devices are limited by the FCC´s regulations. This paper presents a solution to this issue while adding little to the transceiver complexity.